Sewing machine pneumatic needle threader

ABSTRACT

This disclosure relates to a pneumatic needle threader adapted for use in a sewing machine. The needle threader includes structure which permits a needle thread suction conduit to be manually swung from an inoperative storage position within the head of the sewing machine into a cooperative spring-biased engagement with the sewing needle-eye extremity and is utilized to thread the sewing needle.

United States Patent Inventor Robert G. Greulich Crantord, NJ.

Appl. No. 877,709

Filed Nov. 18,1969

Patented Aug. 17, 1971 Assignee The Singer Company New York, N.Y.

SEWING MACHINE PNEUMATIC NEEDLE THREADER 5 Claims, 6 Drawing Figs.

U.S. C1 112/225 Int. Cl D051) 87/00 Field of Search 1 12/225;

[56] References Cited UNITED STATES PATENTS 981,125 l/1911 Schoenfeld 112/225 2,413,014 12/1946 Wall 112/225 3,486,472 12/1969 Kaplan 112/225 Primary ExaminerRichard J. Scanlan, Jr. Att0rneysMarshall J. Breen, Chester A. Williams, Jr. and

Robert E. Smith ABSTRACT: This disclosure relates to a pneumatic needle threader adapted for use in a sewing machine. The needle threader includes structure which permits a needle thread suction conduit to be manually swung from an inoperative storage position within the head of the sewing machine into a cooperative spring-biased engagement with the sewing needle-eye extremity and is utilized to thread the sewing needle.

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WITNESS= SEWING MACHINE PNEUMATIC NEEDLE TI-IREADER SUMMARY OF THE INVENTION This invention relates to structure for automatically threading a sewing needle quickly, easily and without frustration on the part of the operator. Heretofore, keen eyesight and a steady hand were of key importance for threading the needle by hand. Mechanical guides and hooks have been employed presenting the operator with the problem of hook breakage, the hook being necessarily small and comparatively brittle.

Pneumatic needle threaders have also been employed, but

because of structural deficiencies could not'effectively maintain air-sealing engagement with the needle-eye. Oftentimes they have been found to be undesirably clumsy and result in a vestigial accessory not utilized by the operator.

It is an object of the present invention to provide a pneumatic needle threader which is structurally superior to those automatic needle threaders already known in the art in that the arrangement of the present invention facilitates ease in storage, ease in manipulation, minimal visual interference, promotes a substantial air sea] for the effective operation of the needle-threading conduit and equally important it is desirable to utilize.

Another object of this invention is to provide manual pneumatic pump control means which is safely enclosed in the storage vicinity of the needle threader freeing the pump from untimely actuation, but which control means is readily accessible to the operator when the needle threader is to be operated.

It is further object of this invention to provide on the frame of the sewing machine a manual pneumatic pump control means that is strategically located to be manipulated equally well by either a left or right handed operator whereby there need not be an awkward crossing of the operator's arms to interfere with the operator's vision while grasping the loose thread-end with one hand to place it opposite the entrance of the suction conduit and needle-eye while manipulating the manual pneumatic pump control means with the other hand.

DESCRIPTION OF THE DRAWINGS With the above and additional objects and advantages in view as'will hereinafter appear, this invention comprises the devices, combinations and arrangements of parts hereinafter described and illustrated in the accompanying drawings of a preferred embodiment in which:

FIG. 1 represents an elevational view of the head of the sewing machine with the faceplate removed illustrating firstly, the suction conduit in operative engagement with the sewing needle, and secondly, in phantom, the conduit in its inoperative storage position;

FIG. 2 represents an enlarged exploded perspective of the conduit assembly;

FIG. 3 represents an enlarged elevational view of the needle-eye-engaging extremity of the conduit;

FIG. 4 represents an enlarged cross-sectional view through line A -A in FIG. 3 of the needle-eye-engaging extremity of the conduit;

FIG. 5 represents an elevational view of the frame of the sewing machine with the faceplate open and a portion of the head and bed broken away illustrating the pump and pump control mechanism; and

FIG. 6 represents a plan view of the head end of the bracket arm illustrating the pump control mechanism.

DETAILED DESCRIPTION OF THE INVENTION The present invention is illustrated as embodied on a conventional sewing machine having a frame 9 including a worksupporting bed 10, over which is supported a bracket arm 11 terminating in a sewing head 12. Supported for endwise reciprocation in the sewing head 12 is a needle bar 13 having at its lower end a needle clamp 14 in which is detachable secured a sewing needle 15 having an eye 16. A needle-eye reference screw 17 is supported by the needle clamp 14. The needle clamp 14 and the needle 15 each include conventional structure (not shown) adapted to coact with one another for establishing a predetermined orientation of the needle-eye 16 relative to the frame 9. One example of a disclosure of a needle-eye orientation structure may be found in US Pat. No. 2,855,880 issued Oct. 14, l958.to R. E. Johnson. Shiftably supported for vertical movement in the sewing head 12 is a spring-biased presser-bar 18 carrying at its lower end a presser-foot l9.

Pivotally connected to the sewing head 12 by means of a pin 21 is a lever 22. Formed in the lever 22 is a reference slot 23 adapted to coact with the needle-eye reference pin 17 when the lever 22 is pivotally swung downwardly. Fixedly secured to the lever 22 is one extremity 24 of a rigid conduit 25 having two protuberances 26-26 transversely formed thereon. Each protuberance is complemental to a one of two openings 27-27 formed in the free end of the lever 22 adjacent the slot 23. The rigid conduit 25 is fixedly connected to lever 22 by inserting the protuberances 26-26 into the openings 27-27 and deformably upsetting the butt ends of the protuberances 26-26.

The free end portion 28 of the rigid conduit 25 is formed with two mutually perpendicular bends, as at 29-29, and terminates in an opening formed with a needle accommodation slot 30. The slot 30 defines two oppositely faced needle-embracing limbs 31 and 32 with the limb 31 being substantially longer than the limb 32. The limb 31 is made longer than the limb 32 to aid the operator in laterally positioning the slot 30 adjacent the needle 15. The inner walls 33 and 34 corresponding with the limbs 31 and 32 are each formed conically to taper inwardly, and terminate at the rear of the slot in an orifree 35.

The extremity 24 of the rigid conduit 25 fixed to the lever 22 includes a roughened gripping surface 36 formed with equally spaced parallel grooves to aid the operator in manipulating the rigid conduit 25, and terminates in a hollow cylindrical boss 37 onto which may be press-fitted oneextremity of a flexible hose 38.

Urging the slot 30 of the rigid conduit 25 into a substantially air-sealing engagement with the needle-eye 16 is aspring 39 carried by the screw 21, a first limb 40 of which spring 39 bears against the head 12 at 41 and a second limb 42 of which spring 39 bears against the lever 22.

It will be understood from the above that the aforementioned structure permits the rigid conduit 25 to be swung through an arc of approximately 180, as shown in FIG. 1 from an inoperative storage position remote from the needle 15 upwardly extending adjacent the head 12, to a lowered operative needle-engaging position with the slot 30 embracing the needle-eye extremity 16 of the needle 15. Access to the rigid conduit 25 may be had by opening the normally closed faceplate 43 hinged to the sewing head 12 at 44-44, which during the stitching operation of the sewing machine fully encloses the aforementioned conduit structure.

Also positioned within the sewing head 12, as shown in FIG. 5 and FIG. 6 is a manually controlled lever 60 pivotally connected to the head 12 by means ofa screw 61. The free end 62 of the lever 60 is accessible for manual operation upon swinging the hinged faceplate 43 from its normally closed position to its open position, as shown in FIG. 5. A pressing inwardly of the limb 62 will cause the other limb 63 of the lever 60 to engage and operate a conventional electric switch 65 which connects the pneumatic pump to a source of electrical power. The switch 65 is secured to the frame 9 by means of two bracket support screws 66-66. A stop lug 67 is provided on the frame to assist in holding the lever 60 in a predetermined inoperative position inwardly of the path of movement of the faceplate 43.

Fixedly supported beneath the work-supporting bed 10 of the frame 9 by means of the screws 71-71 is a pneumatic pump 100, as shown in H6. 5. The pneumatic pump generally includes a resilient diaphragm 112 in communication with an air inlet port 116 and an air outlet port 117. An endwise reciprocable armature 111 is operatively connected to the diaphragm 112 for deforming the diaphragm and creating a suction airflow in the hose 38, the end 1 18 of which is in communication with the air inlet port 1 16.

In operation, the operator opens the faceplate 43, swings the conduit 25 downwardly placing the slot 30 into embracing engagement with the needle at the needle-eye 16, and depressesthe lever 60 inwardly causing the button 64 to close the switch 65. The switch 65 closes the electric circuit that energizes the pneumatic pump 100 causing the armature 111 to deform the diaphragm 1 12 and generate a suction airflow in the hose 38, which airflow is introduced into the air inlet port 116 and is expelled through the air outlet port 117. The suction airflow is initiated at the orifice 35 opposite the needleeye 16 to draw a thread end placed proximate the needle-eye l6 therethrough and into the conduit 25.

With the needle 15 thus threaded, the operator releases the lever 60, swings the conduit upwardly into its stored position and then closes the faceplate 43 safely and asthetically to enclose the conduit and the pneumatic pump activation lever It will be understood that inasmuch as the location of the free end 62 of the lever 60, which free end 62 the operator depresses, is substantially within the vertical plane extending transversely across the sewing machine frame and containing the axis of the needle bar 13, that the loose thread end may be grasped with either hand, as is most comfortable for the operator, while the operator depresses the free end 62 of the lever 60 with the other hand and in so doing the operator substantially avoids an awkward crossing of his arms or hands that may hinder or interfere with his vision in threading the needle.

It will be further understood that the aforementioned disclosure is merely a description of a preferred embodiment having operator-manipulating means accessible to enable the operator to easily and comfortably utilize and control the pneumatic pump and, therefore, is not to be construed as limiting the spirit of this invention.

Having thus set forth the nature of the invention, what 1 claim herein is:

1. In a sewing machine having a frame terminating in a head, a needle bar supported in said head reciprocation in an endwise path, a sewing needle detachably carried at the lower extremity of said needle bar, a needle-eye formed in said sewing needle, and a needle-eye reference means on said needle bar; a pneumatic needle threader comprising:

a. a conduit adapted to be pivotably supported on said frame, said conduit having a tubular needle-engaging extremity, said tubular needle-engaging extremity having a needle-embracing slot therein including sidewalls and a base wall, said tubular needle-engaging extremity having an orifice opening into the base wall of said needle-embracing slot, the sidewalls of said needle embracing slot tapering out from said basewall each to form a complementary conical surface on opposite sides of the orifice opening;

b. an orifice reference means associated with said conduit adapted to coact with said needle-eye reference means on said needle bar;

c. resilient means acting between said head and said conduit urging said conduit into intimate engagement with said needle whereby said needle-eye is urged into a substantially air-sealing engagement with said orifice;

d. a pneumatic pump means adapted to be supported on said frame in communication with said conduit; and

e. a manual control means associated with said pneumatic pump means to render selectively said pump means operative and inoperative.

2. The combination as claimed in claim 1 wherein said sewing machine includes a faceplate pivotally supported by said frame, said faceplate having an open position and a closed position relative to said frame, said pivotally supported conduit adapted to be swung from an inoperative storage position remote-from said needle to an operative position proximate said needle when said faceplate is in said open position.

3. The combination as claimed in claim 2 wherein said manual control means associated with said pneumatic pump means is accessible when said faceplate is in said open position and concealed when said faceplate is in said closed position, said manual control means including an electric switch means fixedly supported by said frame and a lever pivotally supported by said frame proximate said electric switch means, said lever having a pair of limbs, one limb of said pair of limbs being manually depressible on its free end, the other limb of said pair of limbs correspondingly being shiftably engageable cooperatively with said electric switch means.

4. The combination as claimed in claim 3 wherein said lever means of said manual control means has its manually depressible free end bisected by the vertical plane extending transversely across said frame and containing the axis of said needle bar, whereby said manually depressible free end is located vertically above said needle-eye.

5. A pneumatic needle threader comprising:

a. a conduit having a tubular needle-engaging extremity,

said tubular needle-engaging extremity having a needleembracing slot therein including sidewalls and a base wall, said tubular needle-engaging extremity having an orifice opening into the base wall of said needle-embracing slot, the sidewalls of said needle-embracing slot tapering out from said base wall each to form a complementary conical surface on opposite sides of the orifice opening,

b. a pneumatic pump means in communication with said conduit; and

c. a manual control meansassociated with said pneumatic pump means to render selectively said pump means operative and inoperative. 

1. In a sewing machine having a frame terminating in a head, a needle bar supported in said head reciprocation in an endwise path, a sewing needle detachably carried at the lower extremity of said needle bar, a needle-eye formed in said sewing needle, and a needle-eye reference means on said needle bar; a pneumatic needle threader comprising: a. a conduit adapted to be pivotably supported on said frame, said conduit having a tubular needle-engaging extremity, said tubular needle-engaging extremity having a needle-embracing slot therein including sidewalls and a base wall, said tubular needle-engaging extremity having an orifice opening into the base wall of said needle-embracing slot, the sidewalls of said needle embracing slot tapering out from said basewall each to form a complementary conical surface on opposite sides of the orifice opening; b. an orifice reference means associated with said conduit adapted to coacT with said needle-eye reference means on said needle bar; c. resilient means acting between said head and said conduit urging said conduit into intimate engagement with said needle whereby said needle-eye is urged into a substantially airsealing engagement with said orifice; d. a pneumatic pump means adapted to be supported on said frame in communication with said conduit; and e. a manual control means associated with said pneumatic pump means to render selectively said pump means operative and inoperative.
 2. The combination as claimed in claim 1 wherein said sewing machine includes a faceplate pivotally supported by said frame, said faceplate having an open position and a closed position relative to said frame, said pivotally supported conduit adapted to be swung from an inoperative storage position remote from said needle to an operative position proximate said needle when said faceplate is in said open position.
 3. The combination as claimed in claim 2 wherein said manual control means associated with said pneumatic pump means is accessible when said faceplate is in said open position and concealed when said faceplate is in said closed position, said manual control means including an electric switch means fixedly supported by said frame and a lever pivotally supported by said frame proximate said electric switch means, said lever having a pair of limbs, one limb of said pair of limbs being manually depressible on its free end, the other limb of said pair of limbs correspondingly being shiftably engageable cooperatively with said electric switch means.
 4. The combination as claimed in claim 3 wherein said lever means of said manual control means has its manually depressible free end bisected by the vertical plane extending transversely across said frame and containing the axis of said needle bar, whereby said manually depressible free end is located vertically above said needle-eye.
 5. A pneumatic needle threader comprising: a. a conduit having a tubular needle-engaging extremity, said tubular needle-engaging extremity having a needle-embracing slot therein including sidewalls and a base wall, said tubular needle-engaging extremity having an orifice opening into the base wall of said needle-embracing slot, the sidewalls of said needle-embracing slot tapering out from said base wall each to form a complementary conical surface on opposite sides of the orifice opening, b. a pneumatic pump means in communication with said conduit; and c. a manual control means associated with said pneumatic pump means to render selectively said pump means operative and inoperative. 